Rewards Optimizer
Compare flat cashback vs a card with higher category earn on part of spend.
About this calculator
Many rewards cards market an elevated rate on specific spending categories (groceries, dining, gas) but only pay that rate on the share of your spending that actually falls into those categories, with everything else earning the card's lower base rate -- this calculator models exactly that blend and compares it against a simple flat-rate card. Est. Monthly Rewards (Mix) applies Bonus Category % to the portion of Monthly Spend set by Share in Bonus Categories, and Flat Card % to the remaining share, then adds the two pieces together; Flat Card Monthly, by contrast, applies Flat Card % to all of Monthly Spend with no split.
Annual Difference is simply twelve months of the gap between those two totals, so a small monthly edge compounds into a more meaningful annual figure. Whether the bonus-category card actually wins depends entirely on the relationship between Bonus Category % and Flat Card %, weighted by how much of your spending genuinely lands in the bonus categories: a high Bonus Category % is worth little if Share in Bonus Categories is small, since most spending still earns only the flat rate, while even a modest bonus rate can add up if a large share of spending qualifies for it. This is a rough comparison of blended earn rates -- it does not model annual fees, sign-up bonuses, category caps that many real bonus cards impose (a quarterly or annual spending limit at the elevated rate), or rewards redemption value differences between programs, all of which can change which card is actually the better deal.
Inputs
Results
Est. monthly rewards (mix)
$92.80
≈ 6 movie tickets
How to Use This Calculator
- Enter your Monthly Spend — your typical total card spend per month.
- Set your Flat Card % — the baseline cashback or points rate on a flat-rate card.
- Enter the Bonus Category % — the elevated rate you earn in selected spend categories (groceries, dining, gas, etc.).
- Set Share in Bonus Categories to the percentage of your spend that falls into those bonus buckets.
- Compare Est. Monthly Rewards (Mix) against Flat Card Monthly rewards and Annual Difference to decide which card strategy pays more.
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How the result changes with Monthly spend
| Monthly spend | Est. monthly rewards (mix) |
|---|---|
| $100,000.00 | $2,900.00 |
| $350,000.00 | $10,150.00 |
| $650,000.00 | $18,850.00 |
| $900,000.00 | $26,100.00 |
What each input means
- Monthly spend
- Typical monthly card spend.
- Flat card %
- Baseline cashback rate.
- Bonus category %
- Elevated rate on selected categories.
- Share in bonus categories
- Percent of spend that earns the bonus rate.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersMonthly spend = 3200, Flat card % = 1.5, Bonus category % = 5, Share in bonus categories = 40 = 4 input(s) provided
- Calculate Est. monthly rewardsEst. monthly rewards = spend * (bonusShare * bonus + (1 - bonusShare) * flat)92.8 = $92.8
- Calculate Flat card monthlyFlat card monthly = spend * flat48 = $48
- Calculate Annual differenceAnnual difference = round((bonusEarn - flatEarn) * 12 * 100) / 100537.6 = $537.6
Engine last updated . Checked against 1 independently-derived test — how we verify calculators.
Frequently Asked Questions
When does the bonus-category card actually beat a flat cashback card?
Only when the blended rate -- Bonus Category % applied to Share in Bonus Categories plus Flat Card % applied to the rest -- exceeds the flat card's own rate on all of your spending. If Bonus Category % isn't meaningfully higher than Flat Card %, or if Share in Bonus Categories is small, the bonus card can actually earn less overall despite its higher headline rate, which is exactly what Annual Difference is built to reveal.
Can Annual Difference be negative?
Yes -- if the blended mix rate works out lower than the flat card's rate (for example, a low Share in Bonus Categories combined with a Bonus Category % only slightly above Flat Card %), Est. Monthly Rewards (Mix) comes out below Flat Card Monthly, and Annual Difference is negative. That result means the flat-rate card actually earns more for your spending pattern, not the bonus card.
Does raising Monthly Spend change which card strategy wins?
No -- both Est. Monthly Rewards (Mix) and Flat Card Monthly scale in direct proportion to Monthly Spend, since neither rate changes with spend level in this model, so the winner is determined entirely by the rates and the bonus-category share, not by how much you spend. Raising Monthly Spend widens the gap in dollar terms (Annual Difference grows) without changing which card comes out ahead.
Why does Share in Bonus Categories matter more than the Bonus Category % itself in some cases?
Because Bonus Category % only applies to the portion of spend that Share in Bonus Categories represents -- the rest earns the lower Flat Card % regardless of how generous the bonus rate is. A card offering a very high bonus rate on a narrow sliver of spending can still lose to a flat-rate card if most of your actual spending falls outside that narrow category.
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